Pulsed electromagnetic fields (PEMF) are low-energy, time-varying magnetic fields that are used to treat therapeutically resistant problems of the musculoskeletal system. Those problems include spinal fusion, ununited fractures, failed arthrodeses, osteonecrosis, and chronic refractory tendonitis, decubitus ulcers and ligament and tendon injuries.
The specific problem to which the invention is directed is an improved PEMF spinal stimulation system for providing PEMF therapeutic stimulation to areas of the spinal column undergoing fusion or other repair (such as treatment to salvage a failed fusion).
For spinal PEMF therapy, an electromagnetic transducer is placed on the patient's back such that pulsing the transducer produces an applied or driving field that penetrates to the spinal column. The conventional approach has been to use a single flexibly packaged transducer of wires coupled to a source of driving current. The flexible transducer is conformed to the contour of the patient's back, and strapped into place. By controlling the drive electronics, an appropriate PEMF therapy can be administered.
Current spinal PEMF systems are disadvantageous in at least two respects. To allow a patient to be ambulatory during therapy, additional bracing is usually required to prevent bending that might dislodge or stress the area undergoing treatment. Also, the single transducer configuration fails to take advantage of the flux-aiding effect of a two transducer system to maximize field uniformity.
Accordingly, a need exists for an improved PEMF system that can be used without additional bracing, and provides more uniform active field to the target area than available using a single transducer configuration.